The medical procedure known as peritoneal dialysis has rapidly grown in clinical acceptance as the technique of choice for treating many patients who have lost their kidney function. Typically, the patient is surgically equipped with an implanted catheter (“peritoneal catheter”) which communicates between the peritoneal cavity and the exterior. A dialysis solution is passed into the peritoneal cavity through the peritoneal catheter, whereby diffusion takes place between the dialysis solution and the bloodstream across the peritoneal membrane, which is the lining of the peritoneal cavity. The diffusion process removes waste products that are normally excreted through the kidneys, typically solutes such as sodium and chlorine ions and the other materials normally excreted by the body such as urea, creatinine and water. After a certain period of time, the dialysis solution is removed from the peritoneal cavity, carrying with it diffused breakdown products from the bloodstream. Fresh dialysis solution is then passed into the peritoneal cavity through the peritoneal catheter, and this process of filling and emptying is repeated several times.
Thus, peritoneal dialysis typically involves frequent exchange of dialysis solution. This exchange may be performed manually, usually by the patient, or automatically, by an automated dialysis machine.
In the manual technique, known as Continuous Ambulatory Peritoneal Dialysis (CAPD), dialysis solution is constantly present in the patient's abdomen, but is exchanged several times daily. The exchange is performed manually, typically using gravity to move fluid into and out of the peritoneal cavity. In this process, a fluid path is set up between the peritoneal cavity and a container of fresh dialysis solution or a container for receiving spent dialysis solution, by attaching a patient-side connector (“patient connector”) to a system-side connector (“system connector”) joined with a length of tubing (“line set”) that leads to the container(s). Typically, the patient connector is the peritoneal catheter as such or a separate connector in fluid communication with the peritoneal catheter.
In the automatic technique, known as Automated Peritoneal Dialysis (APD), dialysis machines perform the exchanges of dialysis solution. Similarly to CAPD, a fluid path is set up between the patient and the dialysis machine by attaching a patient connector to a system connector joined with a line set of the dialysis machine.
In all techniques of peritoneal dialysis, peritonitis is one of the most significant risks. Peritonitis can result if connections are made between the patient connector and the system connector in a manner which permits even a very small number of micro-organisms to enter the patient connector and to be flushed into the peritoneal cavity.
Accordingly, the frequent connections which must be made and unmade between the patient and system connectors should be performed in a manner which preserves sterile conditions. These connections are typically performed by the patient or by other non-professionals, which increases the risk for incorrect handling and ingress of micro-organisms.
Conventionally, each time the connection is unmade, the connectors are terminated by capping devices. Before attaching the capping devices, a liquid disinfectant is applied manually onto the connectors. This manual sterilization procedure may, even after training of the person handling the connection, involve a significant risk of infection. There is thus a need for a technique that facilitates the handling while decreasing the risk for infections.
U.S. Pat. No. 7,232,419 discloses a system for maintaining sterile connections during dialysis therapy. The system includes a patient connector, a system connector and a so-called cap. The cap is a disposable device which is configured to be arranged intermediate a connected pair of patient and system connectors. Whenever the system connector is separated from the patient connector, the cap remains on the patient connector. A container body, enclosing a fresh sterile cap, is then attached to the disconnected system connector. At this stage, between treatments, the patient is unconnected to the line set and is allowed to move about freely. In order to reconnect to the line set, the patient removes the cap from the patient connector, and removes the container body from the system connector, leaving the sterile cap on the system connector. The exposed patient connector is then attached to the cap on the system connector, thereby causing a port in the system connector to penetrate a septum valve in the cap so as to enable fluid communication through the connectors. During the reconnection procedure, a front end of the patient connector moves or breaks a ring-shaped seal in the cap to release a disinfectant to sterilize the engagement area between the patient connector and the cap.
The procedure of handling both sterile and non-sterile caps, which are being transferred from system connector to patient connector, is complex and far from intuitive. This prior art system may thus be difficult for untrained persons to handle in a correct manner. In fact, the system relies heavily on correct handling, especially when the system connector is to be protected between treatments. If the system connector is handled incorrectly, micro-organisms may enter the system connector before the container body is attached thereto. Since there is no disinfection between treatments, these micro-organisms will prevail and may later enter the fluid path when the port penetrates the septum valve.